本来是写了几个函数，IP黑名单是记到库里的，为了方便理解，改成了一个class把IP黑名单写了出来。

192.168.1.1 单个IP
192.168.1.* 这样代理 192.168.1.1-192.168.1-255
192.158.1.2-20 这样是代表192.158.1.2-192.158.1.20
也可以这样写 192.168.1.[1|2|3]
嘿嘿～一个方法不知道想法是否周全，拿出来大家讨论
使用
以下是引用片段：
$oBlock_ip = new block_ip();
$oBlock_ip->checkIP();
以下是引用片段：

<?php 
class block_ip { 
var $Block_ip = array("192.168.1.1","210.10.2.1-20","222.34.4.*"); 
function __construct(){ 
} 
function __destruct(){ 
} 
private function makePregIP($str){ 
if (strstr($str,"-")) { 
$aIP = explode(".",$str); 
foreach ($aIP as $k=>$v) { 
if (!strstr($v,"-")) { 
$preg_limit .= makePregIP($v); 
} else{ 
$aipNum = explode("-",$v); 
for($i=$aipNum[0];$i<=$aipNum[1];$i++){ 
$preg .=$preg?"|".$i:"[".$i; 
} 
$preg_limit .=strrpos($preg_limit,".",1)==(strlen($preg_limit)-1)?$preg."]":".".$preg."]"; 
} 
} 
}else{ 
$preg_limit .= $str."."; 
} 
return $preg_limit; 
} 
private function getAllBlockIP(){ 
if ($this->Block_ip) { 
foreach ($this->Block_ip as $k=>$v) { 
$ipaddres = $this->makePregIP($v->start_ip); 
$ip = str_ireplace(".","\.",$ipaddres); 
$ip = str_replace("*","[0-9]{1,3}",$ip); 
$ipaddres = "/".$ip."/"; 
$ip_list[] = $ipaddres; 
} 
} 
return $ip_list; 
} 
public function checkIP() { 
$iptable = $this->getAllBlockIP(); 
$IsJoined = true; 
//取得用户ip 
$Ip = $this->get_client_ip(); 
$Ip = trim($Ip); 
//剔除黑名单中的IP区段 
if ($iptable) { 
foreach($iptable as $value) { 
if (preg_match("{$value}",$Ip)) { 
$IsJoined = false; 
break; 
} 
} 
} 
//如果在ip黑名单中就执行如下操作 
if( !$IsJoined ){ 
echo "IP Error"; 
exit; 
} 
} 
private function get_client_ip(){ 
if (getenv("HTTP_CLIENT_IP") && strcasecmp(getenv("HTTP_CLIENT_IP"), "unknown")) 
$ip = getenv("HTTP_CLIENT_IP"); 
else if (getenv("HTTP_X_FORWARDED_FOR") && strcasecmp(getenv("HTTP_X_FORWARDED_FOR"), "unknown")) 
$ip = getenv("HTTP_X_FORWARDED_FOR"); 
else if (getenv("REMOTE_ADDR") && strcasecmp(getenv("REMOTE_ADDR"), "unknown")) 
$ip = getenv("REMOTE_ADDR"); 
else if (isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], "unknown")) 
$ip = $_SERVER['REMOTE_ADDR']; 
else 
$ip = "unknown"; 
return($ip); 
} 
} 
?>